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PubMed1984

Hematologic and immunologic responses in common marmosets (Callithrix jacchus) infected with Plasmodium knowlesi and Epstein-Barr virus.

The hematologic and immunologic responses to infection with either the Epstein-Barr virus alone or infection with Epstein-Barr virus and Plasmodium knowlesi were studied using common marmosets (Callithrix jacchus). The assays performed included complete blood cell counts, determinations of natural killer cell activity, and determinations of antibody titers to Epstein-Barr virus early antigen, virus capsid antigen and the nuclear antigen. While no animal showed signs of lymphoproliferative disease, it was found that animals infected with Epstein-Barr virus became positive for early antigen, virus capsid antigen and nuclear antigen at low levels. No difference in antibody titers between Epstein-Barr virus infected animals and co-infected animals was observed. An increase also was found in the number of leukocytes in all groups, and an increase in natural killer cells following infection with Epstein-Barr virus. Some depression in natural killer cells was observed in the co-infected animals when compared to Epstein-Barr virus infected animals.

Animals↗

PubMed1984

Stabilities of some constituents of marmoset (Callithrix jacchus) plasma under various conditions of storage.

The stability of various marmoset (Callithrix jacchus) plasma constituents was investigated after storage at room temperature, 4 degrees C, and -20 degrees C. The method of sequential analysis ensured that the between-run bias of the methods of analysis used was drastically reduced, and the definitions of stability were linked to the imprecision of these methods. Optimal conditions for storage for as long as 48 h depended on the analyte being measured. Room temperature was optimal for cholinesterase and acetylcholinesterase; 4 degrees C for protein, albumin, alanine aminotransferase, isocitrate dehydrogenase, sorbitol dehydrogenase, lactate dehydrogenase, and glutamate dehydrogenase; and -20 degrees C for glutathione reductase and alkaline phosphatase. For aspartate amino-transferase and gamma-glutamyltransferase, either 4 degrees C or -20 degrees C would be suitable. Reasons are advanced for some conflicting reports in the published work, and we emphasize the need to investigate each analyte and species separately.

Animals↗

PubMed1984

Ultrastructural aspects of spermatogenesis in the common marmoset (Callithrix jacchus).

The pattern of normal spermatogenesis in the common marmoset, Callithrix jacchus, is described and a system classifying the spermatogenic cycle into nine successive stages is presented. In contrast to most previous studies of spermatogenesis, the classification system developed in this study depends more upon the recognition of characteristic cell associations rather than upon identification of particular steps of spermatid development. The structurally simple acrosome of the marmoset spermatozoon displays insufficiently clear morphological changes during spermatid elongation to allow this to be used as a key to spermatogenic classification. Ultrastructural aspects of spermatogenesis in the marmoset are also described; in general, these correspond to similar descriptions of this process in other primates.

Animals↗

PubMed1981

Supplemental feeding of marmoset (Callithrix jacchus) triplets.

In a colony of marmosets (Callithrix jacchus), all fifteen infants from five sets of triplet births were successfully reared with their parents. Two supplemental feedings were given each infant daily. As an alternative to hand-rearing or foster rearing, the supplemental feeding method eliminated the time-consuming process of hand caring for an infant on a 24-hour per day basis.

Animal Husbandry↗

PubMed1982

Distribution of catecholamine and indoleamine neurons in the brain of the common marmoset (Callithrix jacchus).

The distribution of monoamine neurons in the brains of ten common marmosets (Callithrix jacchus) was examined by means of the Falck-Hillarp formaldehyde histofluorescence technique. Large populations of catecholamine and indoleamine neurons were found throughout the brain stem. Catecholamine cell bodies corresponded essentially to th noradrenaline and dopamine groups defined as A1-A7 and A8-A14, respectively. In contrast to Old World primate species, however, the noradrenaline cell populations (particularly the pontine coeruleal A6 group) were less numerous. Ascending catecholamine fibre pathways were not observed within the medulla or pons, although numerous axons were found near the mesodiencephalic border. These were fine and smooth in appearance in contrast to those of other species and this finding may represent a significant morphological difference. The catecholamine terminal innervation of the diencephalon was modest in the marmoset and was less dense than in other primates. In contrast, limbic areas and the striatum contained very large numbers of terminals. Indoleamine cell bodies, equivalent to the serotonin groups defined as B1-B9, were also observed. The most rostral cell populations (B7-9) were large. In addition, pontine and medullary indoleamine neurons extended laterally through the tegmentum as noted in other primates, such that they often adjacent to catecholamine neurons. A prominent bundle of indoleamine axons was observed in the mesencephalon and corresponded to a fibre pathway seen in rodents and other primates. No terminal varicosities were noted.

Amines↗

PubMed1995

The effect of parturition on the interactions within pairs of common marmosets (Callithrix jacchus).

The relationship within common marmoset (Callithrix jacchus) pairs is based on pair-bond formation. This pair-bond is important for the successful rearing of the young and for the enhancement of reproductive success. Female marmosets bear twins which are carried mainly by males starting on the first day after the birth of the infants. Little is known, however, about the patterns of sociosexual interaction between callitrichid pairs and how these interactions change after the arrival of offspring. To evaluate the effect of parturition on these interactions, three heterosexual pairs of common marmosets were observed for four weeks before and four weeks after the birth of infants. The animals were kept in individual outdoor cages of the Nucleo de Primatologia, under environmental conditions. The time spent in proximity was mainly attributable to the initiative of females before parturition and the initiative of males after the offspring arrived. Males were groomed more before than after the birth of infants. In contrast, the amount of grooming received by females was the same in the two situations. These observations suggest that the relationship within pairs of common marmosets is slightly modified by the birth of infants and indicates that males and females could be using different strategies to enhance their reproductive success.

Animals↗

PubMed1995

Health problems of Callithrix jacchus in captivity.

A 20-year retrospective study was carried out to determine the prevalence of diseases occurring in 265 (155 males and 110 females) common marmosets (Callithrix jacchus), kept at the São Paulo Zoo. A total of 564 clinical disorders were detected: digestive problems, 50.2% (protozoa, 44.3%; helminths, 26.3%; bacteria, 7.0%; non-especific causes, 22.4%); respiratory problems (pneumonia), 16.3%; injuries, 13.8%; nutritional deficiency, 4.4%; reproductive problems (obstetrical) 2.5%; septicemia, 1.6%; circulatory problems, 1.6%; sporadic cases, 4.0%; inconclusive cases, 5.5%. Little attention has been paid to the sanitary care of marmosets in Brazil. Since most of the available information comes from the international literature, the occurrence of major diseases and their etiological agents in Brazil are relevant data.

Animals↗

PubMed1994

Anatomy of adult female common marmoset (Callithrix jacchus) reproductive system.

Better appreciation of the female reproductive anatomy of the common marmoset (Callithrix jacchus) should improve the prospects for nonsurgical embryo transfer in this model. Vaginal measurements were performed in 8 female adult marmoset monkeys. Four monkeys were measured at laparotomy for gross internal anatomy, and 1 monkey was analysed at autopsy. The vagina of the marmoset monkey was found to be divided into a lower and upper vagina with a marked vaginal isthmus between them. The mean lengths of the lower and upper vagina were 17 mm (34 mm in total vagina). The mean uterine size was 8.4 (length) x 10.0 (width) x 6.4 (thickness) mm, with the ovary measuring 5.3 x 4.3 x 3.8 mm. The mean length of the fallopian tube was 10.5 mm with a width of 1.5 mm. Nonsurgical embryo transfer in this model appears to be feasible, but the proportionally long vagina and short uterine cavity needs to be recognised.

Animals↗

PubMedDate not supplied

In vitro activity of two beta-lactam antibiotics against strains of the Bacteroides fragilis group isolated from humans and from Callithrix penicillata marmosets.

The purpose of this study was to determine the in vitro activity of cefoxitin and imipenem against strains of the Bacteroides fragilis group isolated from the intestinal tract of humans and Callithrix penicillata marmosets. The majority of the human and marmosets B. fragilis strains was resistant to cefoxitin. The percentages of resistance to cefoxitin among B. fragilis marmoset strains were higher than those of human origin. On the other hand, the majority of the other Bacteroides of the B. fragilis group isolated from human and marmosets were susceptible to this drug. Imipenem was the most effective beta-lactam drug in this study, and we detected no resistance.

Animals↗

PubMedDate not supplied

Growth factors (EGF, IGF-I) modulate the morphological differentiation of adult marmoset (Callithrix jacchus) Sertoli cells in vitro.

The effects of epidermal growth factor (EGF) and insulin-like growth factor I (IGF-I) on mature marmoset (Callithrix jacchus) Sertoli cells in vitro were investigated using light and electron microscopic and histochemical means. The morphological data were substantiated by morphometric analysis at the electron microscopic level. In a bicameral chamber system, cultured Sertoli cells displayed a high degree of ultrastructural differentiation and exhibited a polarized appearance. Basally located tight junctions joined adjacent cells. Germ cells of early stages of development were regularly seen. Under the influence of IGF-I, cells developed extensive cell-cell contacts. The surface density of smooth endoplasmic reticulum was increased. In contrast, the volume density of lipid inclusions was decreased. The morphological integrity of enclosed germ cells was maintained for a longer period. With EGF, cells were arranged in loose aggregates. Intercellular spaces were widened. The volume density of lipid inclusions was increased. Germ cells exhibited profound signs of degeneration early in culture, paralleled by increased development of phagolysosomes and high acid-beta-galactosidase activity. Under the influence of either growth factor, mitochondria displayed a shift from the crista to the tubulo-vesicular type. Mitochondrial dimensions and the volume density of mitochondrial compartment were increased. In comparison with control cultures all documented changes were statistically significant. Our findings indicate that marmoset Sertoli cells are target cells for EGF and IGF-I. Moreover, the dynamics of intercellular contacts, germ cell survival, and morphological indices of lipid and/or steroid metabolism seem to be differentially modulated.

Animals↗

PubMed1995

Intragastric infection induced in marmosets (Callithrix jacchus) by a Brazilian hepatitis A virus (HAF-203).

Several species of non-human primates have been used in studies on experimental infection with hepatitis A virus (HAV). Attempts to infect a South-American marmoset (Callithrix jacchus) with a Brazilian HAV isolate (HAF-203) are described here. Four seronegative animals were inoculated intragastrically and one was sacrificed on day 11, 20, 47 and 62 after infection. One uninfected animal was included as control. Liver, small intestine, lymph node, spleen and kidney samples were collected for histological diagnosis and immunocytochemistry studies. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) serum enzymes and anti-HAV antibodies were monitored by a colorimetric procedure (Abbott) and an enzyme immunoassay (ELISA), respectively. Feces were collected daily for HAV antigen (HAVAg) detection by ELISA. Increased levels of HAVAg were detected in hepatocytes 11 days after infection, with a gradual decrease during the course of infection. Shedding of HAVAg in feces was observed from the late incubation to the early acute phase (20th day to 47th day after infection). The end of the incubation period was indicated by the initial increases in serum ALT and AST. Severe hepatic lesions such as piecemeal necrosis and bridging necrosis were detected during the acute phase, coinciding with the maximum transaminase levels and the appearance of anti-HAV antibodies. On the 62nd day (convalescent phase), the hepatic tissue showed evidence of regeneration and the transaminase values had returned to baselines. The serological, biochemical, antigenic and histological evidence of hepatitis A was similar to that observed in several primate models inoculated with other HAV isolates.(ABSTRACT TRUNCATED AT 250 WORDS)

Alanine Transaminase↗

PubMed1995

The thyroid gland of Callithrix jacchus in organ culture.

Thyroid glands from 7 marmosets (Callithrix jacchus) of different age groups (newborn, 2 weeks, 2, 7, 8 and 11 months, and 8 years) were grown as organ culture according to Trowell at the medium/air interphase for 3 to 30 days. The morphology of thyroid tissue was well preserved until the end of the culture period. Necroses were only occasionally seen in connective tissue. In contrast to the in vivo situation, the number of lysosome-like inclusions changed considerably and cell-cell contacts became loose. After the addition of TSH the number of apical microvilli, apical granules and coated vesicles rose. The basal surface of follicle cells enlarged due to the formation of processes or ridges and invaginations. Mitosis could be observed. These findings show that, using the Trowell culture technique, thyroid tissue can be grown for up to 4 weeks without showing distinct changes in its morphology. Its responsiveness to the application of TSH is maintained in vitro. Hence, this technique is suitable also for long-term endocrinological, pharmacological and toxicological investigations.

Aging↗

PubMed1995

Visual responses in the lateral geniculate nucleus of dichromatic and trichromatic marmosets (Callithrix jacchus).

New-world primates such as the marmoset (Callithrix jacchus) show polymorphism for the middle- to long-wavelength sensitive cone pigments. Each X-chromosome carries a gene for only one of three possible pigments. All males are thus dichromats, but some females will be trichromats. We have investigated the responses of cells of the parvocellular (PC) and magnocellular (MC) systems within animals from a single marmoset family. The middle- to long-wavelength pigment of dichromats was identified physiologically. Trichromats could readily be distinguished from dichromats by the presence of a high proportion of red-green opponent PC-cells. The physiological classification of phenotypes was confirmed with genetic analysis. The pattern of inheritance was consistent with current genetic models. In trichromatic females, the properties of cells resembled in detail those of cells from the PC- and MC-pathways of the macaque. In dichromats, cell responses resembled those of trichromats (except for the lack of opponency in PC-cells); PC-cells showed sustained and MC-cells transient responses, with a lower contrast gain for the former type. One difference was that a proportion of PC-cells in dichromats showed strong rod input even at high levels of retinal illuminance. Thus, in trichromatic marmosets the presence of two middle- to long-wave pigments appears to permit the elaboration of all the physiological properties associated with trichromacy.

Animals↗

PubMed1997

Characterization of the TCRB chain repertoire in the New World monkey Callithrix jacchus.

Callithrix jacchus is an outbred New World primate characterized by a naturally occurring bone marrow chimerism, restricted polymorphism at many MHC loci, and unusual susceptibility to viral pathogens, adenocarcinoma, colitis, and, following immunization with myelin antigens, a demyelinating disease of the central nervous system closely resembling human multiple sclerosis. Here we characterize the TCRB repertoire in this species, representing the first such analysis in a New World monkey. Two TCRBC, 13 BJ, 2 BD, and 15 BV genes were identified. Overall, a high degree of similarity with human TCRBV-D-J-C gene sequences was observed, indicating a close phylogenetic relationship. Biased usage in favor of genes from the TCRBC1-BJ1 cluster was present in 77% of sequences, in contrast to preferential usage of BC2-BJ2 genes known to occur in humans and mice. Complementarity-determining region 3 averaged 10 amino acids in length and were diverse. Framework regions of TCRBV genes were extensively conserved. Phylogenetic analysis of TCRBV sequences from different species indicated that TCR genes are highly stable across primates. Thus, a diverse TCRB repertoire is generated in C. jacchus despite the limited polymorphism of class I MHC loci. Extensive homology to human TCR genes, natural chimerism, and susceptibility to inflammatory disorders are characteristics of C. jacchus that create a useful model system for the study of human autoimmunity.

Amino Acid Sequence↗

PubMed1997

Morphological analysis of the blue cone pathway in the retina of a New World monkey, the marmoset Callithrix jacchus.

We have studied the components of the short wavelength-sensitive (SWS or "blue") cone pathway in the retina of a New World primate, the marmoset Callithrix jacchus. Of particular interest was the small bistratified ganglion cell, which has been identified in macaque monkey to be the morphological substrate of the blue-ON cell (Dacey and Lee [1994] Nature 367:731-735). Small bistratified cells were intracellularly filled with Neurobiotin in an in vitro retinal wholemount preparation. Their morphology, size, and level of dendritic stratification were similar to their homologues in macaque and human retina. A number of different antibodies were applied to vertical cryostat sections, some of which were cut through the processes of injected small bistratified or parasol ganglion cells. We used antibodies against cholecystokinin (CCK) to label blue cone bipolar cells, and antibodies against the human SWS cone photopigment to label SWS cones. Double-labelled preparations showed that blue cone bipolar cell dendrites contact SWS cone pedicles, and the inner dendrites of the small bistratified cell are costratified with the axon terminals of blue cone bipolar cells. A monoclonal antibody against calbindin was used to label a subpopulation of bipolar cells that stratifies in the outer half of the inner plexiform layer. The axon terminals of these bipolar cells occasionally cross the outer dendrites of small bistratified cells and show extensive costratification with the dendrites of OFF parasol cells. We conclude that an SWS cone pathway with similar connectivity is a preserved feature of the primate visual system.

Animals↗

PubMed1997

Hepatic hemosiderosis in common marmosets, Callithrix jacchus: effect of diet on incidence and severity.

We examined the effect of dietary iron concentration on the incidence of hepatic hemosiderosis in common marmosets (Callithrix jacchus) and assessed the impact of hemosiderosis on animal health. Thirteen young adult common marmosets were fed nutritionally balanced natural-ingredient diets formulated to contain either 100 or 500 ppm of iron. Six were fed the low-iron and seven received the high-iron diet. Baseline blood values and liver iron content were determined for each animal. Animals were weighted monthly, blood work (hematologic analysis, serum iron concentration, total iron-binding capacity, percent of transferrin saturation) was performed semi-annually, and liver biopsies for iron analysis were obtained after marmosets had consumed the test diets for 13 months or at necropsy. Midway in study, the high-iron diet was reformulated to contain 350 ppm of iron because of the death of a male which had consumed that diet for 7 months. Four of seven marmosets fed the high-iron diet died during the first year of the study, compared with one death in the low-iron cohort. The mean increase in liver iron content of the marmosets fed the high-iron diet was 6,371 micrograms/g, dry weight analysis. In contrast the low-iron cohort had a mean decrease of 621.5 micrograms/g. These results indicate that liver iron content can be affected by dietary iron intake. The increased mortality in the marmosets fed the high-iron diet also suggests that hepatic hemosiderosis can be detrimental to marmoset health.

Animals↗

PubMed1997

[Herpesvirus infections in free living black tufted ear marmosets (Callithrix penicillata, E. Geoffroyi 1812) at the State Park of Serra da Tiririca, Niterói, Rio de Janeiro, Brazil].

The mortal cause of black-tufted-ear marmoset (Callithrix penicillata), living in a conservation unit of State Park of Serra da Tiririca-Niterói-RJ, Brasilien, has been investigated in 1995 based on different examinations realized in one animal. After clinical, light and electron microscopic investigations, herpesvirus infection was found to be the etiological agent of the disease.

Animals↗

PubMed1996

Visuotopic organisation of striate cortex in the marmoset monkey (Callithrix jacchus).

The visuotopic organisation of the primary visual cortex (V1) was studied by extracellular recordings in adult male marmosets (Callithrix jacchus) that were anaesthetised with sufentanil/nitrous oxide and paralysed with pancuronium bromide. Extensive sampling of the occipital region in four individuals and partial coverage of V1 in five others allowed not only the establishment of the normal visuotopy but also the study of interindividual variability. As in other primates, there was a single, continuous map of the contralateral hemifield in V1, with the upper visual quadrant represented ventrally and the lower quadrant represented dorsally. The surface area of V1, which was measured in two-dimensional reconstructions of the cortical surface, varied from 192 to 217 mm2. There was a marked emphasis on the representation of the foveal and parafoveal visual fields: the representation of the central 5 degrees of the visual field occupied 36-39% of the surface area of V1, whereas the central 10 degrees occupied 57-59%. No asymmetry between the representations of the upper and lower quadrants was apparent. The visual topography of V1 was highly consistent between individuals, relative to both sulcal landmarks and stereotaxic coordinates. The entire contralateral hemifield was represented in V1; in addition, neurones with receptive fields whose borders invaded the ipsilateral hemifield were observed within V1, less than 800 microns from the V1/V2 boundary. The total invasion of the ipsilateral hemifield was less than 0.5 degree at the centre of the fovea but reached 8 degrees at the periphery of the vertical meridian. Our results demonstrate that the organisation of V1 is similar in diurnal New and Old World simians, despite major variations in size, ecological niche, and timing of postnatal development across species.

Animals↗